Elysium isn't about space stations, it's about wealthy enclaves. Those already exist, and our society is becoming more stratified every year. There's no need for the very rich to leave the planet for that.

Backing up the species is about keeping a strong diverse stock of human genetics and knowledge somewhere safe from whatever harm might befall the earth.

Under those terms, I for one do not care whether it's rich people or poor people. I doubt I'll be in the 0.00001% of the population who are part of it regardless.